US financier and cricket mogul Allen Stanford, held without bail in Texas on charges of a multi-billion-dollar fraud, has been hospitalized, federal law enforcement officials said Thursday.

Stanford was "transported at 6:00 am by ambulance to the Conroe Regional Hospital Center in Texas. He was accompanied by deputies and remains in the custody of the Marshals Service," said US Marshals Service spokesman Dave Turner.

He declined to give details about Stanford's health condition.

The 59-year-old, who awaits his trial in a prison north of Houston, faces up to 375 years in jail if convicted on 21 charges of multi-billion-dollar fraud, money-laundering and obstruction.

Stanford has been struggling to find a lawyer while he sees his Caribbean islands, mansions and a fleet of jets sold off to pay victims of an alleged decade-long, seven-billion-dollar Ponzi scheme.

He has already lost one defense attorney for not paying his bills and was having trouble finding another to defend him without guaranteed compensation.

The court-appointed receiver in the civil case filed in Dallas has seized everything and is selling off the entire lot to compensate jilted investors.

Meanwhile, his former chief financial officer, James Davis, Thursday pleaded guilty to charges stemming from the seven-billion-dollar fraud, the Department of Justice said in a statement.

Davis admitted he and his co-conspirators defrauded investors who bought about seven billion dollars in certificates of deposit administered by the Antigua-based Stanford International Bank.